More same-sex couples may be eligible for Social Security survivor benefits.

Surviving members of same-sex couples who weren’t able to marry because it wasn’t yet legal may be newly eligible for survivor benefits from Social Security.

Even after winning the right to marry across the United States more than six years ago, some same-sex couples have faced challenges accessing certain benefits. To qualify for survivor benefits, for example, couples need to have been married for at least nine months. But some survivors lost their spouses before meeting that threshold, even though they legalized their unions as soon as they were eligible. Others died before they were able to marry at all.

Recent developments ensure that both groups of survivors — those who were able to marry and those who were not — will be permitted to collect benefits: On Monday, the Department of Justice and the Social Security Administration dropped their appeals of two class-action suits in the Ninth Circuit, which had initially ruled in favor of the surviving spouses and partners. And the Social Security Administration had already begun to update its policies last month.

“There are a significant amount of people for whom this could make a significant difference,” said Peter Renn, counsel at Lambda Legal, an advocacy group that represented plaintiffs in the two lawsuits. “Survivor benefits are now equally available to everyone, including potentially thousands of same-sex partners who could not marry their loved ones and may have thought it was futile to apply.”

The group filed the two suits in 2018. One was filed on behalf of Helen Thornton, now 66, who tried to receive benefits on the record of Marge Brown, her partner of 27 years. But Ms. Brown died in 2006, before they were permitted to marry in Washington State, where they lived. The district court in Washington ruled in her favor, but the lawsuit’s protections were limited to people who had applied by Nov. 25, 2020, according to Mr. Renn.

“Now, for the first time, surviving same-sex partners who apply after that date also have the same pathway to survivor’s benefits,” he added.

In the second suit, Michael Ely, now 68, married his partner, James Taylor, shortly after Arizona’s same-sex marriage ban was struck down in 2014. Mr. Taylor died just six months after they married, according to legal documents. Mr. Ely was unable to collect survivor benefits on Mr. Taylor’s earnings record, the legal complaint said, even though they were partnered for more than four decades and Mr. Taylor was the primary earner for the couple.

As long as the deceased person worked long enough, widows and widowers generally may receive survivor benefits as early as age 60, as well as a one-time lump-sum death payment of $255. (Disabled survivors may be eligible at age 50.)

The Social Security Administration and the Justice Department did not immediately comment.

In 2015, a monumental Supreme Court ruling in Obergefell v. Hodges declared that the Constitution guaranteed a right to same-sex marriage, enabling couples across the country to marry even if their states had banned it. That case came after a landmark in 2013, in United States v. Windsor, in which the court ruled that same-sex couples are entitled to federal benefits.

“I can finally breathe a sigh of relief that these benefits are now finally secure,” Mr. Ely said in a statement, “not only for me but for everyone else who found themselves in the same boat.”